Highly pleasing skin appearance is one of the most desired expectations from personal care products from most consumers around the world. In tropical countries where consumers generally have dark skin, there is a desire to have lighter skin appearance. In consumers who live far from the tropical countries e.g. the Caucasian people who generally have lighter skin, there is a need among such consumers to have an even tanned tone of their skin. Any exposure of the skin to sunlight, in such consumers often leads to blotchy skin, referred to as freckles and in some cases they experience hyperpigmentation in localized areas of the skin. Most consumers experience blemishes on their skin after exposure to sun, on healing of wounds or after drying up of acne. Most people, all over the world, notice darker skin on their underarms (i.e in their axilia) as compared to other regions of their skin, although the underarms are rarely exposed to the sun. They prefer an even skin tone in their axilia as compared to other parts of the body. In all of the above cases, consumers rely on cosmetic solutions to their skin appearance problems.
Thus, smooth, soft and glowing skin with even skin tone and colour is desired by all consumers who use personal care compositions for their skin. To provide this benefit, one very commonly used approach is to include sunscreens or sunblocks in such cosmetic products. Another approach to controlling the colour, tone and appearance of the skin is the skin lightening approach where chemicals are added to personal care compositions which alter the formation of melanin in the skin through biochemical transformation in the stratum corneum thereby changing the colour and appearance of the skin. This approach is capable of lightening the skin beyond the basic colour of skin. While this approach has been used successfully in many cosmetic products, researchers are still struggling to improve efficacy of skin lightening agents beyond a certain threshold.
One of the drawbacks of most skin lightening actives used so far is that they are usually synthetically prepared chemical compounds. Synthetic chemicals have over time, taken a negative connotation in the consumer's mind. Hence, many consumers are more and more, preferring actives originating from or extracted from natural sources to be used in such products.
In order to provide a solution to the several drawbacks in the art listed above, the present inventors have been working for many years on deriving actives from natural sources for various personal care benefits. They found to their surprise that fractions of plant material, enriched in butrin beyond a certain minimum percentage exhibit skin lightening activity.
JP 10101543A (Kansai Koso, 1998) discloses a tyrosinase-activity inhibitor that contains, as its effective ingredient, 0.0001 weight percent or more of a flavonoid having OH at sites 2 and 4 such as a chalcone derivative of formula I (R1-R7 are each H or OH, where at least one of sites 2 and 4, or sites 2′ and 4′ is OH, a flavanone of formula II (R8-R10 are each H or OH), a flavone derivative of formula III (R11-R13 are H or OH), or a mixture of them, thereby enabling strong inhibition of tyrosinase activity related to melanin formation.
US 2004115146A (Avon Products) discloses a composition having at least one of the following active extracts Butea frondosa, Naringi crenulata, Stenoloma chusana, or any combinations thereof. There is also provided a composition having at least one of the following additional extracts Azadirachta indica, Glycyrrhiza glabra linn., Morinda citrifolia, tomato glycolipid or any combinations thereof in combination with one or more of the active extracts. The compositions and methods of the invention are effective to lighten hair, skin, lips and/or nails.
The above publications do not disclose a skin lightening composition comprising a plant extract comprising higher than 15% butrin.
It is thus an object of the present invention to provide for a personal care composition that comprises fractions obtained from natural sources that gives enhanced skin lightening as compared to known fractions from natural sources.